TECHNICAL FIELD
The present invention relates, in general, to selection of an on-screen display (referred to hereinafter as "OSD") vertical blanking signal for displaying an OSD signal in a video scanning interval to perform an OSD function of a display apparatus. More particularly, the invention relates to an OSD vertical blanking signal selection circuit for the display apparatus, which is capable of supplying a vertical synchronous signal from a video card as the OSD vertical blanking signal to an OSD circuit when color signals, a horizontal synchronous signal and the vertical synchronous signal are applied from the video card in a separate form. The circuit is also capable of supplying a vertical blanking signal from a vertical deflection circuit as the OSD vertical blanking signal to the OSD circuit when the color signals, horizontal synchronous signal and vertical synchronous signal are applied from the video card in a composite form.